Problem in software engineering exercise

[anon10364]

Sir,
In software engineering exercise question 5 says to create a target in makefile ,checkmemory and use valgrind+grep to check that memory usage is within a certain limit. Sir in this question can we just use valgrind to solve the question or is it necessary to use grep command.Sir basically i am unable to understand why we have to use grep command with valgrind.

Thanks,
Anon10364

[anup]

Anon10364,

If you just use valgrind, how will you figure out whether the memory usage was exceeded? The Makefile target will never fail. If this test were to run on 10000 test cases every night and then let us know in the morning if anything failed we will not be able to automate it. You use grep to extract from this valgrind log how much memory was consumed. Next use some (shell) scripting inside the Makefile to check that the usage is definitely below a threshold.

Thanks,

Anup

[anon10320]

Sir,

I'm using valgrind+grep ./target to checkmemory but it says "command not found" .I'm so confused and what is the intension of changing the name of target in Makefile .

Thanks
anon10320

[anup]

Anon10320,

There is no command valgrind+grep, I am not sure what you are trying to achieve here. The correct way to use valgrind is valgrind -v <file name> | less

Thanks,

Anup

[anon10457]

Hi,

Q5 of medium exercise of Software Engineering Aspects the command
valgrind ./bin/checkmemory < test/test.sql | grep usage should not just display the line where so ever the word 'usage' has come from the output.?
Cos it is not doing the same. I've attached its screenshot also.

[basant]

Anon10457,

Your screenshot clearly shows the memory usage and your command seems to be working fine.

-- Basant

[anon10457]

Hi,

From
valgrind ./bin/checkmemory < test/test.sql | grep usage it should just display the line


==13698== total heap usage : 401 allocs 186 frees , 73835 bytes allocated


Right? Not the other details with it.
But it does not seems to be happening.

Thanks,
Anon10457

[basant]

Anon10457,

Now I get your question.

valgrind ./bin/checkmemory < test/test.sql | grep usage

In the above command, grep is working on stdout. However, valgrind is dumping all the information on stderr. That is grep is not working. If you redirect all stderr output also on stdout, then grep will output lines only with "usage" pattern.

So, try the following.

valgrind ./bin/checkmemory < test/test.sql 2>&1 | grep usage

-- Basant